Design: Randomised controlled trial
Population: 50 children aged 1-14 with nephrotic syndrome and moderate to severe oedema, India
Primary outcome: Cumulative urine output over 48 hours
Effect: 3.13 vs 2.96 mL/kg/h, not significant; 16% stopped combination for weight loss

This Indian randomised trial enrolled 50 children aged 1 to 14 with nephrotic syndrome and moderate to severe oedema. They received furosemide with metolazone or furosemide alone, with urine output and weight monitored for 48 hours.

Mean urine output was 3.13 mL/kg/h with the combination and 2.96 mL/kg/h with furosemide alone, not significantly different. An apparent larger rise from baseline with the combination disappeared after adjustment for baseline output. Weight loss, electrolyte disturbance and length of stay were similar, but 16% in the combination group had enough weight loss to stop treatment.

The trial was small, but it gives no support to starting the combination routinely. It may still have a place in carefully monitored refractory oedema.

Do not add metolazone routinely at presentation of nephrotic oedema.
Reserve combination diuretics for refractory oedema under close monitoring.
Monitor weight, electrolytes and signs of intravascular depletion twice daily on any diuretic.
Watch for hypovolaemia and thrombosis, which diuretics can worsen in nephrotic children.

Why it matters

It suggests a common escalation adds risk without adding diuresis when used from the start.

The statistics, in plain English

With 25 children per group, the trial could miss a modest difference. Adjusting for baseline urine output matters because a group that starts lower can show a larger rise simply by returning toward average.